An acoustic rating tells you how well a floor stops impact noise — footsteps, dropped keys, a chair scrape — from travelling through to the room below. For hybrid flooring in Australian apartments and townhouses, the rating that matters is the AAAC star rating, measured in the field as an LnT,w number in decibels. Lower number, quieter floor, more stars.
Who actually sets the rating
Two bodies set the rules in Australia. The National Construction Code (NCC) covers new builds and major refurbishments. For everything else — swapping carpet for hybrid in a strata unit, renovating a townhouse — the body corporate sets the spec, and most of them follow the Association of Australian Acoustical Consultants (AAAC) guideline. The AAAC is a not-for-profit industry body that publishes star-rating benchmarks for flooring acoustic performance.
The practical takeaway: before you pick a hybrid plank for an upstairs apartment, get the body-corporate by-laws or building manager’s spec in writing. Most strata schemes ask for a minimum of 4 Stars (LnT,w of 50 dB or lower). Some ask for 5 Stars. Building it cheaper than required and getting pulled up after install is the most expensive mistake we see.
The AAAC star rating, in plain numbers
The AAAC rates impact insulation out of 6 stars. The number that backs the rating is LnT,w — the field-measured impact sound pressure level. The “T” means it’s tested in situ, on the actual floor build-up in the actual room, not a lab sample. Here’s how the bands line up:
| Star Rating | LnT,w (dB) | NCC Pass/Fail | Speech audibility from above |
|---|---|---|---|
| 2 Star | ≤ 65 | Fail | Normal speech audible |
| 3 Star | ≤ 55 | Pass | Just audible |
| 4 Star | ≤ 50 | Pass | Not audible |
| 5 Star | ≤ 45 | Pass | Not audible |
| 6 Star | ≤ 40 | Pass | Not audible |
Anything below 3 Stars fails the NCC and isn’t worth specifying for a unit. 4 Stars is the typical minimum for residential strata. 5 and 6 Stars is what you’d target if the body corporate is strict, the slab is thin, or the neighbour below is sensitive to noise.
How a hybrid floor actually hits the rating
The rating isn’t a property of the plank alone — it’s the whole build-up: subfloor, underlay, plank, and the joints. Two things move the number:
- The plank’s attached backing. Most quality hybrid planks ship with a pre-attached IXPE or EVA acoustic foam, typically 1-1.5 mm. That gets you to around 3 Stars on a typical concrete slab.
- The separate underlay. A 5 mm rubber-cork or dense-foam acoustic underlay sits between the slab and the plank. This is where the extra stars come from. A 5 or 6 Star rated underlay is what most strata-grade hybrid installs use.
Some ranges, like Aquacoustic, are built specifically for strata installs — the plank itself has a thicker acoustic backing that hits 5 Stars without an additional underlay roll. That can save labour and floor height in low-ceiling apartments where you can’t lose 7 mm under the door swings.
What to ask the supplier before you buy
A glossy spec sheet that just says “acoustic rated” doesn’t pass a strata audit. Ask three questions:
- What’s the AAAC star rating, and is it for the plank alone or the plank plus a specific underlay? The full system is what gets tested.
- Is there a current AAAC test report? Reports are dated, and an old report on a discontinued product won’t satisfy a body corporate.
- What’s the LnT,w value on a 150 mm concrete slab? That’s the standard reference. If your slab is thinner or you have a timber-joist subfloor, the number will be worse and you’ll need a higher-rated underlay to compensate.
Cost impact
Going from a 4 Star to a 5 or 6 Star build-up usually adds $8-$15 per square metre to the underlay line, plus a small labour difference because the heavier underlay is slower to roll out and trim. On a 70 m² apartment that’s a few hundred dollars — far less than the cost of pulling up a non-compliant floor and reinstalling. We’ve broken the full pricing down in the hybrid flooring cost guide, and the underlay guide walks through which products go with which plank.
Short version
Get the body-corporate spec in writing first, treat the AAAC star rating as the system rating (plank plus underlay, not plank alone), and ask for a current test report. For most Australian apartments, a 5 Star build-up is the safe brief. If you’re still deciding between hybrid and SPC for the unit, the hybrid vs SPC explainer covers the trade-offs, and the best hybrid flooring brands in Australia page lists the ranges we stock with strata-rated options. We’re across acoustic compliance for strata installs in our Sydney and Brisbane showrooms — bring the by-laws in and we’ll match a plank-and-underlay combo to the spec.
Ready to shop? Browse our full hybrid flooring range online, or drop into our Sydney or Brisbane showroom to see the range in person.